Abstract: We present a randomsuccessive nucleation growth model,a two-and a three-dimensional aggregation generation-by-generation model to investigate percolation properties of fractal aggregations with various neighbor conditions and lattice size.Itshows that the percolationthreshold of fractal aggregationisindependent of the lattice size.It dependents onspatial dimension andneighbor conditions,andis aninherent property of the fractal system.The fractal aggregate grows infinitely withthe same fractaldimension whenthe growth probabilityis equal tothe percolationthreshold.The fractal dimension is just a linear function of thespatial dimension.

Key words: fractal, aggregation, percolation, critical properties, Monte Carlo simulation